Revert "Mark libpiex as double_loadable"

This reverts commit c64563c91634c8e6c5fd2dd0b0f67315b30a170f.

Reason for revert: libpiex is no longer used by libmediandk(aosp/915075).
Exempt-From-Owner-Approval: revert
Change-Id: I858a16f7d40613b9c433997bbd7308dcf521427b
1 file changed